Difference between revisions of "WAD files"

Revision as of 20:59, 23 January 2008

WAD Format

The data within a WAD file has the following format.

Header

Start	End	Length	Description
0x000	0x003	4	?? Header size = 0x0020
...	...	...	...

Chain of Certificates

Start	End	Length	Description
0x040	0x043	4	signature type (0x00010001 RSA2048, 0x00010000 RSA4096)
0x044	0x143	256 for RSA2048 (d=0x000), 512 for RSA4096 (d=0x100)	signature
0x144+d	0x17F+d	60	zero filled
0x180+d	0x1BF+d	64	issuer
0x1C0+d	0x1C3+d	4	? subject type (0x00000000, 0x00000001)
0x1C4+d	0x203+d	64	subject
0x204+d	0x307+d	260	? public key
0x308+d	0x30B+d	4	?? unknown (0x00010001)
0x30C+d	0x33F+d	52	zero filled
...	...	...	...

Key and IV

Start	End	Length	Description
0x0bff	0x0c0e	0x0010	Encrypted title key (decrypt using the master key)
0x0c1c	0x0c23	0x0008	First 8 bytes of IV for title key decryption (last 8 bytes are zero)

To obtain the title key, simply decrypt it using the master key and the given IV (last eight bytes zero, first eight bytes supplied).

Note: this is probably part of the TMD/ticket/whatever. I'm throwing the offsets here for now, since this is arguably the most important part for extraction purposes.

File Table

WAD files contain a number of "files" in them. The number of files can be obtained from the halfword (2 bytes) at 0xede. The table itself starts at 0xee4, and it is composed of a number of file entries:

Start	End	Length	Description
0x00	0x03	0x04	File number / ID
0x04	0x05	0x02	First 2 bytes of IV to decrypt contents (last 14 bytes are zero)
0x06	0x07	0x02	Flags ?
0x08	0x0B	0x04	Padding (zero)
0x0C	0x0F	0x04	File size
0x10	0x24	0x14	SHA-1 sum of decrypted file

The files are located after the file table, with their starts aligned to a 64 byte boundary. To read a file, skip bytes until the next 64 byte boundary (unless already at one), read the File size bytes rounded to the next 16 bytes (the AES block size), decrypt using AES (using the title key and the IV in the file table entry plus 14 zero bytes), and take filesize bytes from the result to create the output file. The SHA-1 sum of this should match the one in the file table.

@@ Line 2: / Line 2: @@
 The data within a WAD file has the following format.
-(TO BE CONTINUED)
 === Header ===
@@ Line 104: / Line 102: @@
 | style="border: 1px solid #ccc; padding: 0.2em; background-color: #edd;" | First 8 bytes of IV for title key decryption (last 8 bytes are zero)
 |}
+To obtain the title key, simply decrypt it using the master key and the given IV (last eight bytes zero, first eight bytes supplied).
 Note: this is probably part of the TMD/ticket/whatever. I'm throwing the offsets here for now, since this is arguably the most important part for extraction purposes.